• Pre-heat your oven to 350F and grease and flour a fluted/bundt pan. Whip the butter in a large mixing bowl on high speed for at least two minutes. Add the sugar and continue to whip until soft cream forms. In a small bowl, mix the baking powder into the flour and set aside.
• Add the following ingredients to the mixing bowl, one at a time, and blend after each: addition: Eggs, one at a time, salt, lemon zest.
• Next, add one quarter of the flour and blend; then, add one quarter of the milk and blend. Repeat this process until all of the flour and milk are blended into the batter. Mix the ingredients on medium speed for about five minutes until the texture of the batter has a light and airy, but no more than five minutes. Pour the batter into your greased and floured pan.
• Bake the cake in the preheated oven for 40 minutes. Do not open the oven while the cake is baking or it will not bake properly. Let cool for two hours. Do not remove from the pan.

Make the Lemonade Syrup

• While the cake is baking in the oven, prepare the lemonade mixture: Squeeze the lemons into a pitcher, then add the sugar and mix until the sugar is fully dissolved in the lemon juice. Next, add the water.

Finish

• Once the cake has cooled you can add the lemonade mixture. First, check to ensure you will be able to remove the cake. Since the butter has solidified, it is possible your cake may stick. Place a plate on top of the pan. then tip the pan over and carefully shake the cake out of the pan. Immediately, place the cake pan back onto the cake and carefully turn the pan back over. Remove the plate to expose the cake. This process ensures that the cake will come out when you are ready to serve. If the cake does seem like it wants to stick, you will need to place the cake back in the oven for a few minutes, just to warm the butter, and it will release from the pan easily.
• When you pour the lemonade on the cake, there is a special process to ensure that the cake will be moist throughout. Over thirty minutes: slowly pour a little bit of the lemonade mixture all over the cake in the pan every ten minutes (i.e. three times in total). This will allow the cake to absorb the lemonade mixture very slowly. You should NOT have used all of the lemonade mixture at this point.
• After thirty minutes, tip the lemon cake onto a serving plate and add the remaining lemonade to the top of the cake, distributing it evenly all over the cake.
• Garnish the cake with finely chopped hazelnuts and enjoy.